Grinding wheel dresser



June 6, 1944. J. SNEED GRINDING WHEEL DRESSER Original Filed May 12, 1941 2 Sheets-Sheet 1 firTOENEV June 6, 1944. J. SNEED 2,350,937

GRINDING WHEEL DRESSER Original Filed May 12, 1941" 2 Sheets-Sheet 2 INVENTOR.

a r'rwAP VEY Patented June 6, 1944 2,350,937 GRINDING WHEEL DRESSER John Sneed, Huntington Woods, Mich., assignor to William F. Dalzen, Detroit, Mich.

May 12, 1941, Serial N0.

Original application 393,021, now Patent 2,308,317, dated January 12, 1943. Divided and this application December 16, 194.2,

16 Claims.

The present application is a divisional application of my copending application Serial No. 393,021, filed May 12, 1941, now Patent Number 2,308,317 issued January 12, 1943, relating to a Grinding wheel dresser.

This invention relates to thread grinding machines, and more particularly to dressing mechanisms for the rotatable abrasive grinding wheel of said thread grinding machines.

It is the object herein to provide a dressing mechanism in combination with a thread grinding machine, said mechanism being a universal form dressing mechanism adapted to produce various shaped surfaces in the peripheral edge of the grinding wheel for accurately grinding out various shapes of threads.

It is the object hereof to provide a dressing mechanism which is readily removable from the thread grinding machine and interchangeable with other types of dressing mechanisms.

It is the further object hereof toprovide means for slidably supporting the dressing mechanism upon the grinding wheel support of a thread grinding machine; and also to provide compensating means between said thread grinding machine, said support, and said dresser for raising and lowering the grinding wheel support with a proportional movement of the dresser with respect to said support.

It is the further object of this invention to provide in said dressing mechanism means for removably and adjustably supporting templets for governing the form and shape to be dressed in the peripheral edge of the grinding wheel.

ing in the thread the shape of said templet.

It is the further object hereof to provide in a dressing mechanism, a longitudinally adjustable templet support whereby a plurality of pitches may be reproduced in the grinding wheel with a single templet.

It is thestill further object hereof to provide in a dressing mechanism, a laterally adjustable templet support whereby a proportionately smaller templet maybe used than is required for obtaining a reproduction in the peripheral edge of the grinding wheel.

Other objects will be seen in the various arrangements of parts and combinations thereof as will be hereinafter described in connection with the appended drawings, of which;

Serial No. 469,253

Fig. 1 is an end elevational view of the dressing mechanism.

Fig. 2 is a side elevational view of the thread grinding machine and the dresser, mechanism.

Fig. 3 is a top plan view of the dressing mechanism, and

Fig, 4 is an elevational section on line 4-4 of Fig. 3.

The above drawings illustrate merely preferable embodiments of the invention, it being expressly understood that it is not intended that the invention be limited thereby.

In the drawings, the grinding wheel dresser is generally indicated at A with its housing I I vertically and reciprocably mounted within the support l2 with friction minimizing ball races I3 interposed therebetween. Support i2 is joined to the vertically movable grinding wheel support l4 and is adapted to move therewith. v

Hand wheel connection I5 operating through suitable gears and a threaded shaft supported by column I9, raises and lowers housing I4 and the abrasive grinding wheel I6 with respect to said column. The dresser Aand its housing H are also raised and lowered by hand wheel l5 operating through the movable wheel support 14.

Lever I! has a lug slidable within the vertical support l2. Said lever is centrally pivoted at point 20 to the movable housing l4 thereby providing an adjustable support for the pivot point 20. g

The other end of lever I! also has a lug 2i for adjustable engagement with respect to column 19 at point 22.

An adjustable relation is maintainedbet-ween lever I1 and column I 9 as the wheel supporting housing M is downwardly fed, whereb the dresser is permitted ta properly engage the peripheral surface of the grinding wheel l6 in operative dressing position.

A'compensating screw 23 is longitudinally disposed within the bracket member 24 secured to ually'operable adjusting means permitting longitudinal adjus tment' or said compensating screw l8 on its end adapted to 23 whereby the lever 11 is correspondingly adjusted as desired.

Housing [4 slides relatively to column 19 with a suitable dovetail connection; and is adjustable with respect thereto by operation of the hand wheel connection 15. Y

From time-to time the grinding wheel 16 becomes worn requiring a dressing operation; or on the other hand it may be desired to vary the form of the cutting edge thereof for grinding a particular shape of thread.

For these purposes the wheel dresser A is employed having a housing ll vertically and reciprocably mounted within the support l2 as above described, in connection with theFigures 1, 2 and 3.

The above dressing mechanism is a universal form dresser adapted to obtain any desired shape of peripheral grinding edge on the grinding wheel 16 depending upon the particular desired. 4

By utilizing the support 12 as illustrated in Figures 1, 2, 3 and 4 and the ball races or ways l3 it is seen that dresser A desired.

Referring to Figures 1, 2, 3 and 4 the dresser housing H has seeured thereto the laterally disposed guide table 23 fo the slidable dovetail block 29 which is adapted for l ngitudinal reciprocable adjustment in a slot 3111;; said guide table. Block 29 is also slotted at 3| to provide a dovetail support for the transversely slidable templet support 32 to which is removably secured templet 33 by bolts 34.

Said. templet is a. pattern from which the dressing device is manually controlled and from which is governed the dressing action of a diamond 35 within a suitable mounting 36 for obtaining a peripheral edge on the grinding wheel 16 similar in form to the particular templet chosen. To obtain any particular'thread shape or pitch it will be seen that a plurality of templets 33 may be available for removable attachment to the laterally movable support 32'.

h ollw r b r 1 with a handle 38, provided upon its lower surface with a wedge shaped edge 33, as better seen in Fig. 1, is pivoted atone end within housing H by means of a ball pivot 40 with its shank {ll secured thereto.

A diamond mounting 36 provisioned within the follower bar 31,"is adjustably secured therein preferably by a set screw 45. Referring to Figure 4 it is seen that said diamond mounting 36 is adapted to engage grinding wheel l6, and is manipulated with respect thereto by the follower bar 31 so as to reproduce in said peripheral edge a shape corresponding to the shape of the particular templet 33 which is secured to bracket32.

In operation, with the edge 39 positioned at the central point of the templet,;,the' follower bar is manually or mechanically'moved laterally over the surface thereof, which in turn governs the direction of cutting edge of the diamond 3.5 in mountin .6.

Referring to Figure 4 the dresser housing H has a slotted opening for receiving the extended shank portion 56 of the ball pivot '40. Itwill be noted that the central point'of extension '56 is directly above the central point of the ball pivot By means, of the slotted guide 55 lever 31 can- .nottilt laterally about the pivot 40,but it"will be seen that said bar 31 may only be translated rm o th e the peripheral edge of the y H is easily removable and interchangeable with any other type of dresser if 'ber 2,308,317 issued cause so pivoted the shape as long as in vertical and horizontal planes for following the contour of the templet 33.

In dressing the grinding wheel in making reasonably large included angles between threads as for instance in the neighborhood of forty-five degrees or greater, it isnot necessary for the diamond to tilt as it is translated over the peripheral surface of the grinding wheel, because with such an angle or with similar angles, the noncutting edges of the diamond will not come in contact with the grinding wheel. However in the caseof small included angles between the threads the pivoted diamond as set out in my co-pending application Serial No. 393,021, now Patent Num- January 12, 1943, relating to a Grinding wheel dresser, is more desirable bediamond is presented normally to the surface of the grinding wheel.

The diamond 35 in this embodiment has a cone shaped point with a flat surface on one face thereof. A block 51 may be disposed on the under side of bar 31 and suitably secured thereto by screws 58. Said block may be of any desired it is similar in cross section to the cross section of the'diamond employed.

Applicant preferably arranges the distance between the pivot 40 and the diamond 35, and the distance between the pivot 49 and the templet 33, in the ratio of one to-ten. Consequently the width of block 51 is ten times the width of the cutting face of diamond 35, whereby the shape of the templet is correctly reproduced-on the peripheral edge of the grinding wheel Iii for obtaining a predetermined pitch.

However it is seen that the diamond moves onetenth as far as the bar 31 at the point where block 51 engages the templet. In-grinding Whitworth threads the bottom of the diamond 35 is given a radius or curvature of, for instance, threethousandths of an inch. In order that the templet may be properly reproduced in the surface of the grinding wheel it is necessary that the bottom templet engaging edge of" block 51 also have a radius so that the cross sectional shape thereof continues to-correspond to the shape of the diamond.

In applicants preferable embodiment the ratio of one to ten is employed, and therefor the radius in the bottom ofthe block 51 will be thirtythousandths of an inch. It will 'be understood that it might be desirable to employ a diamond with a different radius where a different pitch is required. In which case it becomes necessary to provide a corresponding block 51 with a proportionately corresponding radius. Block 51 is therefore removable'and interchangeable with other blocks having different curvatures at their templet engaging surfaces.

It will be understood that the following limitations however must be imposed-upon the-angular inclination of the block 5'I.' In order that the sides of the diamond do not contact the grinding wheel it is necessary'that the included angle of the block be equal to the included'angle or the diamond, or even'sli'ghtly. greate'r'so as to provide the necessary clearanceof the sides of said diamond andthe grinding wheel'. Similarly so the included angle of'the' block should beslightly less than the included angle ofth'e'templet.

For regulating laterally 'the resultant'form of the peripheral edge" on the grinding wheel 16, means are-provided for laterally moving the'templ'et nol'der'32. These means consistofa templet compensating lever :46'vn'than extending finger 41 adapted to slidably actuate the templet holder 32 within the limits provided by the micro-calibrated stops 50and I. i

The dressing operation is carried out in two steps. First with the templet holder properly positioned against stop 50, edge 39 is centrally positioned with respect to the templet 33, and then moved outwardly in one direction over onehalf of the surface thereof, With diamond 35 engaging the rotating wheel I6.

The compensating lever 46 is then actuated until bracket '32 engages the stop 5|. In this position the edge 39 of bar 31 is again centrally positioned upon the templet 33 and the bar is moved laterally in the opposite direction over the surface of said templet.

By providing for lateral adjustment of the templet with respect to the diamondcarrying bar during the dressing operation, the templet used may be smaller than would otherwise be required. It has been found that in dressing in one direction or the other over the grinding wheel that as the diamond reaches the crest or topmost edge of the grinding surface of the grinding wheel that the top edge thereof chips off as the diamond proceeds to go up and over the top thereof and down on the other side.

By employing a broad flat topped surface in the templet the diamond is started at the central most point in the periphery of the grinding wheel merely by placing the follower bar at the central point in the top surface of the templet. The diamond is then alternately brought down from the center of the grinding wheel edge on only one side or the other of the grinding edge thereby eliminating undesirable chipping.

Member 29 is longitudinally slidable upon the support 28 within dovetail slot 30 for a very definite purpose. It is seen that by sliding said support that the distance between the templet 33 and the diamond 35 varies with respect to the fixed distance between said diamond and the pivot support 46. Thus it will be seen that by longitudinally sliding the support 29 a plurality of different pitches may be obtained from a single templet.

This becomes apparent when it is seen that longitudinal adjustment of the templet varies the proportional movement of the diamond with respect to the grinding wheel, while the movement of the follower bar with respect to the surface of the templet remains substantially the same, Thus as the templet is moved towards the pivotal point 40, it is seen that the diamond moves a greater distance than when the templet is in its intial outermost position. The pitch defined in the grinding edge is thu smaller because the diamond moving further laterally provides thicker threads and thus less threads to the inch which is the measure of the pitch.

By a suitable calibration the longitudinal movement of a particular templet to certain predetermined points will result in accomplishing different predetermined pitches for the particular templet used. By employing the sliding support 29 it will be seen that considerable time is saved whenever it is desired to change the pitch of the thread to be out by the grinding wheel I6, within the limits of movement of said support. Furthermore, considerable expense is eliminated .by

providing one templet which by movement ofsupport 29 permits the dressing of a plurality of pitches in said grinding wheel.

Follower bar 31 is readily removable from housing I I for adjustment or changing of the diamond 35. Referring to Figure 1, the release stud 5,2

is 'adjustably threaded: within housing I I and is adapted to cooperatively engage the pivot All for retaining the same within said housing. The opposite side of said pivot is engaged by a suitable relatively permanent stud 53. By loosening stud 52, the follower bar 31 may be easily withdrawn from housing II. A locking screw 54 as shown in Figure 1, is employed for retaining said stud 52. I

It is understood that handle 38. may be replaced by a suitable handle bar or other means providing for two-handed manipulation of bar 31.

As above described templet support 29 is longitudinally adjustable upon the table 28 for obtaining a plurality of pitches in the peripheral edge of the grinding wheel with the use of a single templet.

Where this longitudinal adjustment is desired, the block 51 must be extended longitudinally over the length of follower bar 3'! upon the under side thereof, as shown by the dotted lines in Figure 4.

Having thus described my invention, reference should now be had to the claims which follow forming a part thereof, in which I claim:

1. A dressing mechanism for the grinding wheel of a thread grinding machine. comprised of a housing with a longitudinally disposed slotted recess therein, adapted to adjustment with respect to said wheel, a follower bar pivotally supported within said housing, a shank member thereon extending above the pivotal support of said bar, with its end disposed within said slotted recess, a diamond carried by said bar, adapted to engage said grinding wheel, a longitudinally and laterally adjustable templet support carried by said housing, a templet carried thereby, and means for translating said follower bar over the surface of said templet for reproducing its shape by said diamond in the peripheral edge of said grinding wheel, the movement of saiddiamond with respect to said wheel being limited to horizontal and. vertical directions.

2. A dressing mechanism for a thread grinding wheel comprised of a housing adapted to adjustment with respect thereto, a follower bar pivotally supported within said housing, a diamond carried by said bar adapted to engage said grinding wheel, a templet carried by said housing and longitudinally adjustable thereon, a guide means longitudinally disposed and secured upon the under side of said bar for engaging at its edges the surface of said templet, said guide means being gradually tapered along its templet engaging edges, whereby the proportion between the width of the cutting face of the diamond and the width of the guide means at the longitudinally adjusted position of the templet is equal to the proportion of distances between the pivot and said templet and the pivot and said diamond, and means for translating said follower bar over the surface of said templet for reproducing its shape by said diamond in the peripheral edge of said grinding wheel, the movement of said diamond with respect to said wheel being limited to horizontal and vertical directions.

3. A dressing mechanism for a thread grinding wheel comprised of a housing adapted to adjustment with respect thereto, a follower bar pivotally supported within said housing, said housing having. a slotted recess therein, means upwardly extending above the pivotal support of said bar slidably disposed within said recess, to prevent radial tilting of said bar, a diamond-car- 'ried by said bar adapted to engage saidgrinding wheel, a templet carried by said housing and longitudinally adjustable thereon, a guide means longitudinally disposed and-secured upon the under side of said bar for engaging the surface of said templet, and means for translating said follower -bar-over the surface of said templet for reproducing its shape by said diamond in the peripheral edge ofsaid grinding wheel,

4. *A dressing mechanism for the grinding wheel of a thread grinding machine comprised of a housing with a --longitudinally disposed slotted recesstherein, adapted to adjustment with respect to said wheel, a follower bar pivotally supported within said housing, thereon extending above the pivotal support, of said bar, with itsend disposed within said slotted recess, a diamondcarried by said bar, adapted to engage said grinding wheel, a longitudinally and laterally'adjustable templet support carried by said housing; a templet carried thereby, guide means longitudinally disposed and secured upon the under side of said bar for engaging the surface of said templet, the depth of said guide being proportionately greater than the width of the cutting face of said diamond, and means for translating said follower bar over the surface of said templet for reproducing its shape-by said diamond in the peripheral edge of said grinding wheel.

5. A dressing mechanism for a grinding wheel comprised of a housing with a longitudinally disposed slottedrecess therein, a follower bar pivotally supported within said housing, said support comprising a ball universally supported within said housing, and a shank member thereon secured to said'bar and extending above the same with its end disposed within said slotted recess, a diamond carried by said bar adapted to engage saidgrinding wheel, a longitudinally and laterally adjustable templet support'carried by said housing, a templet carried thereby, and means for translating said follower bar-over the surface of said templet for reproducing its shape .by said diamond in the peripheral edge of said grinding wheel, the movement of said diamond with respect to said wheel being limited to horizontal and vertical directions.

6. A dressing mechanism for a grinding wheel comprised of a housing with a recess therein, a follower bar pivotally supported within said housing, means upwardly extending above the pivotal support of said bar transversely ofsaid bar slidably disposed within said recess, a diamond carried by saidbar', adapted to engage said grinding'wheel, a longitudinally and laterally adjustable templet support carried by said housing, a templet carried thereby, and means for translating said follower bar over the surfaceofsaid templet for reproducing its shape by said diamond in the peripheral edge of said grinding wheel, the movement of said diamond with respect to said wheel being limited to horizontal and vertical directions. 7 V

'7. 'A dressing mechanism for a grinding wheel comprised of a housingwith a recess therein, a follower bar pivotally supported within said housing, a shank member thereonextending above the pivotalsupport of said'bar, with its ,end portion guidingly disposed carried by said baradapted-to engagesaid grinding wheel, a longitudinally'and laterally adjustable support carried bysaid housing, a templet carried thereby and means-for translating said follower "bar over the surface of said templet a shank member within said recess, a diamond said recess,-a diamond carried by comprised of a housing 'in g sa id support comprising a supported within said housing, and a shank memyfsaid diamond in whereby the shape thereof isreproduced with the size thereof reduced in the peripheral edge of the grinding wheel bysaid diamond, the movement of said-diamondwith respect to said wheel being limited'tohorizontal and vertical directions. 1

8-. A dressingmechanism fora grinding wheel comprised-of a housing with a slotted recess therein,- a follower bar pivotally supported within said housing, a shank member thereonextending-above the pivotal support of said bar, with its-endportion disposed within said recess, a diamond carried by said bar adapted to engage saidgrindin'gwheel in non-tilting relation, a 1ongitudin'ally' and laterally adjustable templet carried by said housing, and means for translating said followerbar over the surface of said templet for reproducing its'shape by said diamond in the peripheral edge of said grinding-Wheel.

9.- A'dressing mechanism for a grinding wheel comprised of a housing with a recess therein, a followerbar =pivotally-supportedwithin said housing,-- said support comprising a ball universally upported within said housing, and a shank member'thereon secured to said bar and extending above the same with its end disposed within said recess, a diamond carried by said bar adapted to engage said grinding wheel in non-tilting relation, -a longitudinally and laterally adjustable templet carried by said housing, and means for translating said follower bar over the surface of said templet for reproducing its shape by said diamond intheperipheral edge of said grindin 10. A dressing mechanism for a grinding wheel comprised of a housing with a recess therein, a

follower bar pivotally supported within said housing, said support comprising a ball universally supported within said housing, and a shank member thereon secured to said bar and extending abovethe same with its enddisposed within said recess,- a diamond carried by said bar adapted to engage said grinding wheel in non-tilting relation, a laterally adjustable templet carried by said-housing,-and means for translating said follower bar over the surface of said templet for reproducing its shape by said diamond in the peripheral edge of said grinding wheel.

1'1-. A dressing mechanism for a grinding wheel comprised of a housing with a recess therein, a

"follower bar pivotally supported Within said housing, said'support comprising a ball universally supported within said housing, and a shank member thereon secured to said-bar and extending-above *the same with its end disposed within said bar adapted toflengage said grinding wheel in non-tilting relation; a longitudinally adjustable templet car'- ried by said housing, and means for translating said follower bar over the surface of said templet for reproducing its shape by said diamond in the peripheral edge of said grinding wheel;

12; A dressing'mechanism'for a grinding wheel with a recess therein, a follower bar pivotally supported within said housball universally benthereon -secured to said bar and extending "above the same with its end disposed within said recess,-a diamond carried by said bar adapted toeng-age said grinding wheel in-non-tilting relat-io'n,---a templet carried by said housing, and means for translating said follower bar over the surfac "of said templet-for reproducing its shape y the peripheral edge of said grinding wheel.

13. A dressing mechanism for a grinding wheel comprised of a housing with a recess therein, a follower bar pivotally supported within said housing, means upwardly extending above the pivotal support of said bar transversely of said bar slidably disposed within said recess, a diamond carried by said bar, adapted to engage said grinding wheel in non-tilting relation, a longitudinally and laterally adjustable templet carried by said housing, and means for translating said follower bar over the surface of said templet for reproducing its shape by said diamond in the peripheral edge of said grinding wheel.

14. A dressing mechanism for a grinding wheel comprised of a housing with a recess therein, a follower bar pivotally supported within said housing, means upwardly extending abovethe pivotal support of said bar transversely of said bar slidably disposed within said recess, a diamond carried by said bar, adapted to engage said grinding wheel in non-tilting relation, a templet carried by said housing, and means for translating said follower bar over the surface of said templet for reproducing its shape by said diamond in the peripheral edge of said grinding wheel.

15. A dressing mechanism for a grinding wheel comprised of a housing with a recess therein, a

follower bar pivotally supported within said housing, a shank member thereon extending above the pivotal support of said bar, with its end portion guidingly disposed within said recess, a diamond carried by said bar adapted to engage said grinding wheel in non-tilting relation, a longitudinally adjustable templet carried by said housing, and means for translating said follower bar over the surface of said templet whereby the shape thereof is reproduced with the size thereof reduced in the peripheral edge of the grinding wheel by said diamond.

16. A dressing mechanism for a grinding wheel comprised of a housing with a slotted recess therein, a follower bar pivotally supported within said housing, a shank member thereon extending above the pivotal support of said bar, with its end portion disposed within said recess, a diamond carried by said bar adapted to engage said grinding wheel in non-tilting relation, a longitudinally adjustable templet carried by said housing, and means for translating said follower bar over the surface of said templet for reproducing its shape by said diamond in the peripheral edge of said grinding wheel.

JOHN SNEED. 

